1. Field of the Invention
This invention relates to replaceable machine parts that are exposed to high wear and repeated shock loading, such as teeth used on dragline buckets. Specifically, the system of this invention comprises a new and improved retention system permitting easier and quicker changeovers of high-wear replaceable parts.
2. Description of the Prior Art
Digging and levelling apparatus such as draglines, backhoes, front-end loaders and like often use replaceable tooth assemblies which are mounted on the tooth horns to provide sacrificial parts that are exposed to the repeated shock loading and high wear occasioned by the digging operation. In such systems, each tooth assembly typically includes a wedge-shaped adapter which mounts directly on the tooth horn of the bucket, shovel or alternative digging or scraping mechanism of the equipment. A wedge-shaped tooth point is frontally seated on and rigidly pinned to the adapter for engaging the material to be excavated.
Attachment of the tooth point is typically accomplished by means of one or more inserts which are inserted into insert cavities in an adapter. The inserts are internally threaded to accommodate a bolt that secures the tooth to the adapter. Installation and removal of teeth secured using such a system requires substantial time and effort, since the tooth point bolts must be screwed in and unscrewed when the tooth is to be replaced, operations which requires using a powered impact wrench. Moreover, the use of such a tool presents the danger of over-torquing, resulting in damage to the threads and possible personal injury to the operator.
I have discovered that by using a pin featuring spring-loaded balls along the shank instead of a threaded bolt, along with an insert having one or more internal grooves to accommodate the spring-loaded balls. A pin including such a mechanism can be inserted manually, without tools, and removed quickly and easily using a pair of pliers or a special extraction tool designed to fit a hook built into the pin.
The invention is particularly suited to accomplish quicker and easier replacement of teeth used for excavating equipment such as draglines, bucket wheels, but also is applicable to other types of equipment having sacrificial parts subject to high wear.
It is an object of this invention, therefore, to provide quicker changeovers for sacrificial parts of machines, especially digging equipment.
It is a further object of this invention to provide an improved system for attaching replaceable teeth to drag line buckets and similar equipment.